PolynomialAdditionCSLL

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
typedef struct node * NODE;
struct node
{
  int coeff, x, y, z;
  struct node *link;
};
NODE POLY1=NULL, POLY2=NULL, POLYSUM=NULL, tailPOLYSUM=NULL, temp, ptr, tail=NULL;
NODE newNode()
{
  NODE X;
  X=(struct node*)malloc(sizeof(struct node));
  X->link=NULL;
  X->coeff=X->x=X->y=X->z=-1;
  return X;
}
NODE readPolynomial()
{
  int terms;
  ptr=newNode();
  ptr->link=ptr;
  printf("\nEnter the number of terms in the Polynomial: ");
  scanf("%d",&terms);
  printf("\nEnter the Coefficient, degrees of x, y and z of the %d terms in decreasing order: ",terms);
  for(int i=1;i<=terms;i++)
  {
    temp=newNode();
    temp->link=ptr;
    scanf("%d%d%d%d",&temp->coeff,&temp->x,&temp->y,&temp->z);
    if(ptr->link==ptr)
      ptr->link=tail=temp;
    else
    {
      tail->link=temp;
      tail=temp;
    }
  }
  return ptr;
}
void displayPolynomial(NODE head, char Poly)
{
  printf("\nThe entered Polynomial %c is: ",Poly);
  for(ptr=head->link;ptr!=head;ptr=ptr->link)
  {
    printf("%d*x^%d*y^%d*z^%d",ptr->coeff,ptr->x,ptr->y,ptr->z);
    if(ptr->link!=head)
      printf(" + ");
  }
  printf("\n");
}
void storePolynomialC(int coeff, int x, int y, int z)
{
  if(!POLYSUM)
  {
    POLYSUM=newNode();
    POLYSUM->link=POLYSUM;
  }
  temp=newNode();
  temp->link=POLYSUM;
  temp->coeff=coeff;
  temp->x=x;
  temp->y=y;
  temp->z=z;
  if(POLYSUM->link==POLYSUM)
    POLYSUM->link=tailPOLYSUM=temp;
  else
  {
    tailPOLYSUM->link=temp;
    tailPOLYSUM=temp;
  }
}
void addPolynomial()
{
  NODE ptrA,ptrB,ptrC;
  int found=0;
  for(ptrA=POLY1->link;ptrA!=POLY1;ptrA=ptrA->link)
  {
    for(ptrB=POLY2->link;ptrB!=POLY2;ptrB=ptrB->link)
    {
      if(ptrA->x==ptrB->x && ptrA->y==ptrB->y && ptrA->z==ptrB->z)
      {
        found=1;
        storePolynomialC(ptrA->coeff+ptrB->coeff, ptrA->x, ptrA->y, ptrA->z);
        break;
      }
    }
    if(!found)
      storePolynomialC(ptrA->coeff, ptrA->x, ptrA->y, ptrA->z);
    else
      found=0;
  }
  found=0;
  for(ptrB=POLY2->link;ptrB!=POLY2;ptrB=ptrB->link)
  {
    for(ptrA=POLY1->link;ptrA!=POLY1;ptrA=ptrA->link)
    {
      if(ptrA->x==ptrB->x && ptrA->y==ptrB->y && ptrA->z==ptrB->z)
      {
        found=1;
        break;
      }
    }
    if(!found)
      storePolynomialC(ptrB->coeff, ptrB->x, ptrB->y, ptrB->z);
    else
      found=0;
  }
  printf("\nThe resultant Polynomial C is: ");
  for(ptrC=POLYSUM->link;ptrC!=POLYSUM;ptrC=ptrC->link)
  {
    printf("%d*x^%d*y^%d*z%d",ptrC->coeff,ptrC->x,ptrC->y,ptrC->z);
    if(ptrC->link!=POLYSUM)
      printf(" + ");
  }
  printf("\n");
}
void evaluatePolynomialA()
{
  int x,y,z,result=0;
  displayPolynomial(POLY1,'A');
  printf("\nEnter the values of x, y and z: ");
  scanf("%d%d%d",&x,&y,&z);
  for(ptr=POLY1->link;ptr!=POLY1;ptr=ptr->link)
    result+=ptr->coeff*pow(x,ptr->x)*pow(y,ptr->y)*pow(z,ptr->z);
  printf("\nThe result after evaluating the Polynomial A is: %d",result);
  printf("\n");
}
int main()
{
  int choice;
  while(1)
  {
    printf("\nSelect an operation\n1) Enter Polynomial A\n2) Display Polynomial A\n3) Enter Polynomial B\n4) Display Polynomial B\n5) Add Polynomial A and Polynomial B\n6) Evaluate Polynomial A\n7) Exit\n>| ");
    scanf("%d",&choice);
    switch (choice)
    {
      case 1:
        POLY1=readPolynomial();
      break;
      case 3:
        POLY2=readPolynomial();
      break;
      case 2:
        displayPolynomial(POLY1, 'A');
      break;
      case 4:
        displayPolynomial(POLY2, 'B');
      break;
      case 5:
        addPolynomial();
      break;
      case 6:
        evaluatePolynomialA();
      break;
      case 7:
      {
        printf("\nThank you for using the program");
        exit(0);
      }
      break;
      default:
        printf("\nInvalid Choice\n");
    }
  }
}